The insecticidal protein produced by Bacillus thuringiensis (hereinafter referred to as a “Cry toxin”) exerts an insecticidal activity against certain species of insects. The Cry toxin produced by Bacillus thuringiensis serovar israelensis is known to be toxic to mosquito larvae.
The inventors fixed the Cry toxin to a polyhedron of polyhedrin protein, which is a protein microcrystal produced by Bombyxmori cypovirus (BmCPV). The Cry toxin fixed to the polyhedron is hereinafter referred to as a “Cry polyhedron”. A tag for fixing the Cry toxin to the polyhedron of polyhedrin protein was added to the N-terminal of the Cry toxin. Then the tagged Cry toxin was fixed to the polyhedron of polyhedrin protein.
The inventors reported that
(1) the Cry polyhedron exerted an insecticidal activity against mosquito larvae, and
(2) mosquito larvae which ingested the Cry polyhedron died (refer to the non-patent literature 1).
On the other hand, a method for making mosquito larvae easily ingest the Cry polyhedron at their habitat in natural environment was not found at that time.